Crystal growth of solvothermally obtained LiFePO4 in dependence of synthesis conditions

Abstract

Olivine type LiFePO4 is a promising cathode material for the use in lithium ion batteries, especially in the batteries for hybrid electric vehicles or pure electric vehicles. In this work, LiFePO4 was synthesized by solvothermal method at 180oC, for 15 hours. The n-hexanol was used as a solvent with cyclohexane and Triton X-100 as co-solvent and surfactant, respectively. The powders were annealed at elevated temperatures with addition of oxalic acid as carbon source. The conditions of solvothermal synthesis and the presence of the oxalic acid played important role in the crystal growth mechanism. Powders were characterized by X-ray diffraction, scanning electron microscopy and galvanostatic charge-discharge cycling.